#!/usr/bin/env python3
# -*- coding: utf-8 -*-
 
r'''
learning.py
 
A Python 3 tutorial from http://www.liaoxuefeng.com
 
Usage:
 
python3 learning.py
'''
 
import sys
 
def check_version():
 v = sys.version_info
 if v.major == 3 and v.minor >= 4:
  return True
 print('Your current python is %d.%d. Please use Python 3.4.' % (v.major, v.minor))
 return False
 
if not check_version():
 exit(1)
 
import os, io, json, subprocess, tempfile
from urllib import parse
from wsgiref.simple_server import make_server
 
EXEC = sys.executable
PORT = 39093
HOST = 'local.liaoxuefeng.com:%d' % PORT
TEMP = tempfile.mkdtemp(suffix='_py', prefix='learn_python_')
INDEX = 0
 
def main():
 httpd = make_server('127.0.0.1', PORT, application)
 print('Ready for Python code on port %d...' % PORT)
 httpd.serve_forever()
 
def get_name():
 global INDEX
 INDEX = INDEX + 1
 return 'test_%d' % INDEX
 
def write_py(name, code):
 fpath = os.path.join(TEMP, '%s.py' % name)
 with open(fpath, 'w', encoding='utf-8') as f:
  f.write(code)
 print('Code wrote to: %s' % fpath)
 return fpath
 
def decode(s):
 try:
  return s.decode('utf-8')
 except UnicodeDecodeError:
  return s.decode('gbk')
 
def application(environ, start_response):
 host = environ.get('HTTP_HOST')
 method = environ.get('REQUEST_METHOD')
 path = environ.get('PATH_INFO')
 if method == 'GET' and path == '/':
  start_response('200 OK', [('Content-Type', 'text/html')])
  return [b'<html><head><title>Learning Python</title></head><body><form method="post" action="/run"><textarea name="code" style="width:90%;height: 600px"></textarea><p><button type="submit">Run</button></p></form></body></html>']
 if method == 'GET' and path == '/env':
  start_response('200 OK', [('Content-Type', 'text/html')])
  L = [b'<html><head><title>ENV</title></head><body>']
  for k, v in environ.items():
   p = '<p>%s = %s' % (k, str(v))
   L.append(p.encode('utf-8'))
  L.append(b'</html>')
  return L
 if host != HOST or method != 'POST' or path != '/run' or not environ.get('CONTENT_TYPE', '').lower().startswith('application/x-www-form-urlencoded'):
  start_response('400 Bad Request', [('Content-Type', 'application/json')])
  return [b'{"error":"bad_request"}']
 s = environ['wsgi.input'].read(int(environ['CONTENT_LENGTH']))
 qs = parse.parse_qs(s.decode('utf-8'))
 if not 'code' in qs:
  start_response('400 Bad Request', [('Content-Type', 'application/json')])
  return [b'{"error":"invalid_params"}']
 name = qs['name'][0] if 'name' in qs else get_name()
 code = qs['code'][0]
 headers = [('Content-Type', 'application/json')]
 origin = environ.get('HTTP_ORIGIN', '')
 if origin.find('.liaoxuefeng.com') == -1:
  start_response('400 Bad Request', [('Content-Type', 'application/json')])
  return [b'{"error":"invalid_origin"}']
 headers.append(('Access-Control-Allow-Origin', origin))
 start_response('200 OK', headers)
 r = dict()
 try:
  fpath = write_py(name, code)
  print('Execute: %s %s' % (EXEC, fpath))
  r['output'] = decode(subprocess.check_output([EXEC, fpath], stderr=subprocess.STDOUT, timeout=5))
 except subprocess.CalledProcessError as e:
  r = dict(error='Exception', output=decode(e.output))
 except subprocess.TimeoutExpired as e:
  r = dict(error='Timeout', output='执行超时')
 except subprocess.CalledProcessError as e:
  r = dict(error='Error', output='执行错误')
 print('Execute done.')
 return [json.dumps(r).encode('utf-8')]
 
if __name__ == '__main__':
 main()